a. Brief Summary and Field of the Invention
The invention relates to a lock for locking a motor vehicle steering column, the lock comprising a locking element displaceable reciprocally to-and-fro between locked and unlocked positions and a control element which is rotatable about an axis in opposite directions to-and-fro by a drive to axially displace the locking element, or a drive element cooperating with the locking element, in either direction, the control element surrounding the locking element or its drive element and comprising two inner bevel surfaces which cooperate with two radial projections of the locking element or of its drive element that are situated on diametrically opposed sides of the axis of rotation of the control element, and which each merge at each of the respective two ends into a terminal surface that is situated in a plane orthogonal to the axis of rotation of the control element.
b. Related Art
A lock of this kind is known wherein the locking element may be advanced exactly up to the locked or unlocked position but no farther, not even if the control element should subsequently rotate further, i.e. even if its drive should not instantaneously stop as soon as the locking element has reached the locked or the unlocked position. The locking element or its drive element and the control element are configured in a coaxial manner and cooperate by means of the two radial projections of the inner locking element or its inner drive element that are mutually aligned and opposite diametrically with respect to the axis of rotation of the control element and that are each displaceable orthogonally relative to the axis of rotation of the control element and spring-loaded, and by means of the two inner bevel surfaces of the outer control element and one terminal surface of one bevel surface and the corresponding terminal surface of the other bevel surface, which terminal surfaces are disposed in a common plane that extends orthogonal to the axis of rotation of the control element and each extend up to beside the other or the one of the bevel surfaces, and they cooperate in such a way that the locking element or its drive element shall be commensurately axially displaced upon rotation of the control element in that direction in which the projections move on the bevel surfaces toward the terminal surfaces, and that, when the projections pass from the bevel surfaces to the terminal surfaces, the locking element or its drive element shall be motionless and remain in the attained axial position until the control element is rotated in the opposite direction so that the projections will move on the bevel surfaces away from the terminal surfaces, and the locking element or its drive element will move in the opposite axial direction until the projections move from the bevel surfaces to their other terminal surfaces which also extend in a common plane which extends orthogonal to the axis of rotation of the control element. The projections of the locking element or of its drive element may comprise two pins mounted in a common cross borehole of the locking element or its drive element and being loaded by a common helical compression spring (German patent 44 36 326).
An object of the invention is to further improve the known lock and in particular to further reduce the number of elements of the lock, to further simplify assembly and to further lower manufacturing costs.